KR101077457B1 - Process for production of highly pure quaternary ammonium salt - Google Patents

Abstract

(1) A quaternary ammonium hydroxide or quaternary ammonium carbonate is added to a quaternary ammonium salt containing a protonate of a tertiary amine as an impurity, and the protonate of the tertiary amine is added to quaternary ammonium. Neutralized with hydroxide or quaternary ammonium carbonate to convert to tertiary amine and water, while the quaternary ammonium hydroxide or quaternary ammonium carbonate is converted to quaternary ammonium salt,

(2) A method for producing a high purity quaternary ammonium salt, wherein the produced tertiary amine and water are removed out of the system.

High purity quaternary ammonium salt, manufacturing method of high purity quaternary ammonium salt.

Description

Production method of high-purity quaternary ammonium salt {PROCESS FOR PRODUCTION OF HIGHLY PURE QUATERNARY AMMONIUM SALT}

The present invention provides a method for producing a quaternary ammonium salt which reduces the protonates of tertiary amines and tertiary amines contained as impurities in quaternary ammonium salts used as electrolytes for power storage devices such as electric double layer capacitors and electrolytic capacitors. It is about.

Conventionally, the method for preparing the quaternary ammonium salt is a quaternary ammonium halide by reacting an alkyl halide with a tertiary amine, and an acid is reacted with this, and a diester carbonate is reacted with a tertiary amine. It is known to produce ammonium salts and then to react the acid to decarbonate.

If neither method is fully quaternized with the tertiary amine, the unreacted tertiary amine reacts with the acid in a subsequent process to produce the protic acid salt of the tertiary amine, the primary product being quaternary Incorporation into the ammonium salt.

In addition, tertiary amines may be produced by thermal decomposition of quaternary ammonium halides or quaternary ammonium salts. The resulting tertiary amine produces a protonate of the tertiary amine in the preparation of the quaternary ammonium salt. Since the hydrogen atom of the cation of the protonate of the tertiary amine is easily released as a proton, it is particularly unstable to the reduction reaction, which is known to cause breakdown voltage and long-term reliability of the electric double layer capacitor and the electrolytic capacitor (eg For example, patent document 1).

Therefore, in order to obtain highly reliable electric double layer capacitors and electrolytic capacitors, it is necessary to reduce the protonates of the tertiary amine and the tertiary amine in the quaternary ammonium salt used as the electrolyte.

As a method for reducing the protonate of the tertiary amine and the tertiary amine in the quaternary ammonium salt, a method of recrystallizing the salt in an organic solvent is known (Patent Documents 1 and 2).

However, it is not suitable as an industrial method, such as a fall of a yield by recrystallization. In addition, when the quaternary ammonium salt is a liquid substance at room temperature, it is difficult to recrystallize.

An object of the present invention is to provide a method for producing a quaternary ammonium salt which reduces the protonates of tertiary amines and tertiary amines contained as impurities in the quaternary ammonium salts.

[Patent Document 1] Japanese Unexamined Patent Publication No. 2000-311839

[Patent Document 2] Japanese Patent Application Laid-Open No. 2004-186246

<Start of invention>

The present invention relates to the following inventions.

1. (1) A quaternary ammonium hydroxide salt or quaternary ammonium carbonate is added to a quaternary ammonium salt containing a protonate of a tertiary amine as an impurity, and the protonate of the tertiary amine is added to the fourth. Neutralized by quaternary ammonium hydroxide or quaternary ammonium carbonate to tertiary amine and water, while the quaternary ammonium hydroxide or quaternary ammonium carbonate is converted to quaternary ammonium salt,

(2) A method for producing a high purity quaternary ammonium salt, wherein the produced tertiary amine and water are removed out of the system.

2, (1) reacting a tertiary amine with an alkyl halide which may have a substituent to obtain a quaternary ammonium halide salt,

(2) an acid compound is reacted to obtain a quaternary ammonium salt containing a tertiary amine protic acid salt as an impurity,

(3) To this, quaternary ammonium hydroxide or quaternary ammonium carbonate is added, and the protonate of the tertiary amine is neutralized with quaternary ammonium hydroxide or quaternary ammonium carbonate to form tertiary amine And quaternary ammonium hydroxide or quaternary ammonium carbonate to quaternary ammonium salt

(4) A method for producing a high purity quaternary ammonium salt, wherein the produced tertiary amine and water are removed from the system.

In this invention, the protonate of a tertiary amine means the tertiary amine salt which has H <^+> which can be released in a molecule | numerator.

(1) The quaternary ammonium hydroxide salt or the quaternary ammonium carbonate is added to the quaternary ammonium salt containing the protonate of the tertiary amine as an impurity to remove the protonate of the tertiary amine. Neutralized by quaternary ammonium hydroxide or quaternary ammonium carbonate to tertiary amine and water, while quaternary ammonium hydroxide or quaternary ammonium carbonate is converted to quaternary ammonium salt, (2) The resulting tertiary amine and water are a process for producing a high purity quaternary ammonium salt which is removed out of the system.

As the quaternary ammonium cation of the quaternary ammonium salt used in the present invention, for example, tetraalkylammonium, tetraalkylphosphonium, imidazolium, pyrazolium, pyridinium, triazium, pyridazinium, thiazolium, oxa Zolium, pyrimidinium, pyrazinium, etc. are mentioned.

Specifically, the following compounds can be shown, for example.

As tetraalkylammonium, tetraethylammonium, tetramethylammonium, tetrapropylammonium, tetrabutylammonium, triethylmethylammonium, trimethylethylammonium, dimethyldiethylammonium, trimethylpropylammonium, trimethylbutylammonium, dimethylethylpropylammonium, methylethyl Propylbutylammonium, N, N-dimethylpyrrolidinium, N-ethyl-N-methylpyrrolidinium, N-methyl-N-propylpyrrolidinium, N-ethyl-N-propylpyrrolidinium, N, N- Dimethylpiperidinium, N-methyl-N-ethylpiperidinium, N-methyl-N-propylpiperidinium, N-ethyl-N-propylpiperidinium, N, N-dimethylmorpholinium, N-methyl -N-ethylmorpholinium, N-methyl-N-propylmorpholinium, N-ethyl-N-propylmorpholinium, trimethylmethoxymethylammonium, dimethylethylmethoxymethylammonium, dimethylpropylmethoxymethylammonium, Dimethylbutylmethoxymethylammonium, diethylmethylmethoxymethylammonium, methylethyl Lofilmethoxymethylammonium, Triethylmethoxymethylammonium, Diethylpropylmethoxymethylammonium, Diethylbutylmethoxymethylammonium, Dipropylmethylmethoxymethylammonium, Dipropylethylmethoxymethylammonium, Tripropylmethoxymethyl Ammonium, Tributylmethoxymethylammonium, Trimethylethoxymethylammonium, Dimethylethylethoxymethylammonium, Dimethylpropylethoxymethylammonium, Dimethylbutylethoxymethylammonium, Diethylmethylethoxymethylammonium, Triethylethoxymethylammonium , Diethylpropylethoxymethylammonium, diethylbutylethoxymethylammonium, dipropylmethylethoxymethylammonium, dipropylethylethoxymethylammonium, tripropylethoxymethylammonium, tributylethoxymethylammonium, N-methyl -N-methoxymethylpyrrolidinium, N-ethyl-N-methoxymethylpyrrolidinium, N-propyl-N-methoxymethylpyrrolidinium, N-butyl-N-methoxymethylpyrrolidinium, N -methyl -N-ethoxymethylpyrrolidinium, N-methyl-N-propoxymethylpyrrolidinium, N-methyl-N-butoxymethylpyrrolidinium, N-methyl-N-methoxymethylpiperidinium, N -Ethyl-N-methoxymethylpyrrolidinium, N-methyl-N-ethoxymethylpyrrolidinium, N-propyl-N-methoxymethylpyrrolidinium, N-methyl-N-propoxymethylpyrrolidinium , 4-azoniaspiro [3,4] octane, 3-azoniaspiro [2,4] heptane, 5-azoniaspiro [4,4] nonane, 6-azoniaspiro [5,5] undecane, etc. Can be mentioned.

As tetraalkyl phosphonium, tetraethyl phosphonium, tetramethyl phosphonium, tetrapropyl phosphonium, tetrabutyl phosphonium, triethylmethyl phosphonium, trimethyl ethyl phosphonium, dimethyl diethyl phosphonium, trimethyl propyl phosphonium, trimethyl butyl Phosphonium, dimethyl ethyl propyl phosphonium, methyl ethyl propyl butyl phosphonium, and the like.

Examples of imidazolium include 1,3-dimethylimidazolium, 1-ethyl-3-methylimidazolium, 1,3-diethylimidazolium, 1,2-dimethyl-3-ethylimidazolium, 1, 2-dimethyl-3-propyl imidazolium etc. are mentioned.

Examples of pyrazolium include 1,2-dimethylpyrazolium, 1-methyl-2-ethylpyrazolium, 1-propyl-2-methylpyrazolium, 1-methyl-2-butylpyrazolium and the like.

Examples of pyridinium include N-methylpyridinium, N-ethylpyridinium, N-propylpyridinium, and N-butylpyridinium.

Examples of the triazolium include 1-methyltriazolium, 1-ethyltriazolium, 1-propyltriazolium, 1-butyltriazolium and the like.

Examples of the pyridazinium include 1-methylpyridazinium, 1-ethylpyridazinium, 1-propylpyridazinium, 1-butylpyridazinium and the like.

Examples of thiazolium include 1,2-dimethylthiazolium and 1,2-dimethyl-3-propylthiazolium.

Examples of oxazolium include 1-ethyl-2-methyloxazolium, 1,3-dimethyloxazolium and the like.

Examples of pyrimidinium include 1,2-dimethylpyrimidinium, 1-methyl-3-propylpyrimidinium, and the like.

Examples of pyrazinium include 1-ethyl-2-methylpyrazinium and 1-butylpyrazinium.

As the anion of the quaternary ammonium salt used in the present invention, for instance ^{_{CF 3 CO 2 -, CF 3}} SO 3 -, BF 4 -, AlF 4 -, ClBF 3 -, (FSO 2) 2 N -, PF 6 ^{_{-, AsF 6 -, ClO 4}} -, N (CF 3 SO 3) 2 -, C (CF 3 SO 3) 3 -, RfSO 3 -, RfCO 2 - ( However, Rf is a fluoroalkyl group having 1 to 8 carbon atoms the _{^{indicated), (R r1 SO 2)}} (R r2 SO 2) N -, (R r1 SO 2) (R r2 CO 2) - ( However, R ^r1, R ^r2 is a fluoroalkyl group having 1 to 8 carbon atoms And R ^r1 and R ^r2 may be the same or different). Preferably CF ₃ CO ₂ ^- may be mentioned ^{_{-, CF 3 SO 3 -,}} BF 4 -, AlF 4 -, ClBF 3 - or (FSO _{2) 2} N.

Examples of the quaternary ammonium cation of the quaternary ammonium hydroxide or quaternary ammonium carbonate used in the present invention include the same as those listed as the quaternary ammonium cations of the quaternary ammonium salt.

The protonate of the tertiary amine, which is an impurity of the present invention, is produced when the quaternary ammonium salt is prepared. It is also produced when the quaternary ammonium salt undergoes thermal decomposition. Specifically, for example, when synthesizing the BF ₄ salt of N-methoxymethyl-N-methylpyrrolidinium, hydrochloric acid contained as an impurity in chloromethylmethyl ether of the raw material is a tertiary amine which is another raw material. Reacts with methylpyrrolidine to produce a protonate of methylpyrrolidine. Or chloromethylmethyl ether is hydrolyzed by methylpyrrolidine or a trace amount of water contained in the solvent to produce hydrochloric acid, thereby producing a protic acid salt of methylpyrrolidine by the same reaction. The protic acid salt becomes HBF ₄ salt of methylpyrrolidine which is very difficult to remove by a salt conversion reaction using HBF ₄ . In addition, even when BF ₄ salt synthesis was carried out at a high temperature of 130 to 200 ° C., a small amount was obtained by thermal decomposition of N-methoxymethyl-N-methylpyrrolidinium salt (hydrochloride, BF ₄ salt), but HBF ₄ of methylpyrrolidin Salts are formed. In case of using the methylpyrrolidine in excess, N- methoxymethyl -N- methylpyrrolidin-pyridinium hydrochloride in the methylpyrrolidine and the residual, ensuing N- methylpyrrolidone in a change to a pyridinium HBF ₄ salt HBF ₄ Produces a salt.

Specifically as a tertiary amine, the following compounds can be shown, for example.

Triethylamine, trimethylamine, tripropylamine, tributylamine, dimethylethylamine, dimethylpropylamine, dimethylbutylamine, diethylmethylamine, diethylpropylamine, diethylbutylamine, dipropylbutylamine, dibutylpropyl Amine, methylethylpropylamine, methylethylbutylamine, ethylpropylbutylamine, N-methylpyrrolidine, N-ethylpyrrolidine, N-propylpyrrolidine, N-butylpyrrolidine, N-methylpiperi Dean, N-ethylpiperidine, N-propylpiperidine, N-butylpiperidine, N-methylmorpholine, N-ethylmorpholine, N-propylmorpholine, N-butylmorpholine, dimethylmethoxy Methylamine, diethylmethoxymethylamine, dipropylmethoxymethylamine, dibutylmethoxymethylamine, ethylmethylmethoxymethylamine, methylpropylmethoxymethylamine, methylbutylmethoxymethylamine, ethylpropylmethoxymethyl Amine, ethylbutylmethoxymethylamine, propylbutylmethoxymethylamine, dimethyl Methylamine, diethylethoxymethylamine, dipropylethoxymethylamine, dibutylethoxymethylamine, ethylmethylethoxymethylamine, methylpropylethoxymethylamine, ethylpropylethoxymethylamine, ethylbutylethoxy Methylamine, propylbutylethoxymethylamine, N-methoxymethylpyrrolidine, N-ethoxymethylpyrrolidine, N-propoxymethylpyrrolidine, N-butoxymethylpyrrolidine, N-ethoxy Methyl pyrrolidine, N-propoxymethylpyrrolidine, etc. are mentioned.

1-methylimidazole, 1-ethylimidazole, 1,2-dimethylimidazole, 1-methyl-2-ethylimidazole, etc. are mentioned.

As pyrazolium, 1-methylpyrazole, 1-ethylpyrazole, 1-propylpyrazole, 3-methylpyrazole, etc. are mentioned.

Pyridine, triazole, pyridazine, pyrazine, 1-methylthiazole, 1-methyloxazole, etc. are mentioned.

As the protic acid salt of the tertiary amine, specifically, the tertiary amine CF ₃ CO ₂ H, CF ₃ SO ₃ H, HBF ₄ , HAlF ₄ , HClBF ₃ or (FSO ₂ ) ₂ NH, HPF ₆ , HAsF ₆ , HClO ₄ , NH (CF ₃ SO ₃ ) ₂ , HC (CF ₃ SO ₃ ) ₃ , RfSO ₃ H, RfCO ₂ H (where Rf represents a fluoroalkyl group having 1 to 8 carbon atoms), ( R ^r1 SO ₂ ) (R ^r2 SO ₂ ) NH, (R ^r1 SO ₂ ) (R ^r2 CO ₂ ) H (wherein R ^r1 , R ^r2 represents a fluoroalkyl group having 1 to 8 carbon atoms, R ^r1 , R ^r2 may be the same or different).

The manufacturing method of the high purity quaternary ammonium salt of this invention is demonstrated below.

The quaternary ammonium halide salt is prepared by reacting a tertiary amine of a raw material with an alkyl halide which may have a substituent. The quaternary ammonium salt is then prepared by reacting the quaternary ammonium halide salt with an acid compound.

As the acid compound, for example, CF ₃ CO ₂ H, CF ₃ SO ₃ H, HBF ₄ , HAlF ₄ , HClBF ₃ , (FSO ₂ ) ₂ NH, HPF ₆ , HAsF ₆ , HClO ₄ , NH (CF ₃ SO ₃ ) ₂ , CH (CF ₃ SO ₃ ) ₃ , RfSO ₃ H, RfCO ₂ H (where Rf represents a fluoroalkyl group having 1 to 8 carbon atoms), (R ^r1 SO ₂ ) (R ^r2 SO ₂ ) NH, (R ^r1 SO ₂ ) (R ^r2 CO ₂ ) H, provided that R ^r1 and R ^r2 represent a fluoroalkyl group having 1 to 8 carbon atoms, and R ^r1 and R ^r2 may be the same or different. have. Preferably CF ₃ CO ₂ H, CF ₃ SO ₃ H, HBF ₄ , HAlF ₄ , HClBF ₃ or (FSO ₂ ) ₂ NH.

At this time, in the quaternary ammonium salt, a trace amount of the protonate of the tertiary amine is contained as an impurity from the tertiary amine derived from the raw material.

Subsequently, quaternary ammonium hydroxide or quaternary ammonium carbonate is added to the quaternary ammonium salt containing the impurity to react (neutralize). As the addition amount of the quaternary ammonium hydroxide or the quaternary ammonium carbonate, 0.5 to 10 equivalents, preferably 0.5 to 2 equivalents, and more preferably 1 to 2 equivalents, relative to the number of moles of the protonate of the tertiary amine .

As temperature to add, -20 degreeC-200 degreeC, Preferably 10 degreeC-100 degreeC is good. More preferably, 25 to 80 degreeC is good. The reaction time is 10 minutes to 20 hours, preferably 30 minutes to 5 hours.

After the reaction, the quaternary ammonium hydroxide or quaternary ammonium carbonate is converted to quaternary ammonium salt, and the protonate of the tertiary amine is converted to tertiary amine and water. The method of distilling off tertiary amine and water can be distilled by a conventional method, and can also be reduced-pressure or heating, or these can be combined. Moreover, while heating, nitrogen, argon, air, etc. which do not react with a quaternary ammonium acid salt can be blown in and removed.

The temperature at which the tertiary amine and water are distilled off is 20 to 200 ° C, preferably 90 to 170 ° C. The time is 0.5 to 24 hours, preferably 5 to 18 hours.

The quaternary ammonium salt after impurity removal has reduced protonates of tertiary amines and tertiary amines as impurities.

The high-purity quaternary ammonium salt produced in the present invention can be suitably used as an electrolyte or an electrolyte such as an electric double layer capacitor, an electrolytic capacitor, a battery, and the like. The content of the protonate of the tertiary amine in the electrolyte required for such a nonaqueous electrolyte electrolyte is preferably smaller from the viewpoint of lowering the electric double layer capacitor, the electrolytic capacitor or the battery breakdown voltage, and the long term reliability. Preferably it is 200 ppm or less, More preferably, it is 100 ppm or less, Especially preferably, it is 30 ppm or less. Most preferably, it is 10 ppm or less.

The concentration of the protonate of the tertiary amine can be analyzed by liquid chromatography. Analysis by liquid chromatography can be performed, for example, on the conditions shown below.

Column Inertsil

ODS-3 250mm * 4.6mm ID 5.0μm (made by GE Science), detector L-7490 RI detector (made by Hitachi Seisakusho), mobile phase {Na ₂ HPO ₄ 1 mM + KH ₂ PO ₄ 9 mM + NaClO ₄ 100 mM} / H ₂ O, flow rate 1.0 mL / min, column temperature 40 ° C.

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Hereinafter, although this invention is demonstrated concretely based on an Example, it is not limited to this at all.

Example 1

N, N to N-methoxymethyl-N-methylpyrrolidinium tetrafluoroborate containing 410 ppm of N-methylpyrrolidine / HBF ₄ salt in a glove box having an dew point of -60 ° C in an argon atmosphere. 0.2 g of, N-triethyl-N-methylammonium hydroxide aqueous solution (35% by weight) was added and reacted for 2 hours while inhaling nitrogen at 5 L / min at 130 ° C. After the completion of the reaction, the mixture was kept at 25 ° C for 1 hour under a reduced pressure of 1 mmHg. The dew point was returned to normal pressure with argon gas at -60 ° C and used for analysis. The content of N-methylpyrrolidine-HBF ₄ salt was below the detection limit (10 ppm).

Example 2

N, N, N-triethyl-N-methylammonium hydroxide to 100 g of N-methoxymethyl-N-methylpyrrolidinium tetrafluoroborate containing 410 ppm of N-methylpyrrolidine / HBF ₄ salt 0.2 g of aqueous solution (35% by weight) was added and reacted for 2 hours while inhaling nitrogen at 5 L / min at 120 ° C. The content of N-methylpyrrolidine-HBF ₄ salt was below the detection limit (10 ppm).

Example 3

N-methoxymethyl-N-methylpyrrolidiniumtetrafluoroborate containing 410 ppm of N-methylpyrrolidine / HBF ₄ salt in a glove box having an dew point of -60 ° C in N-meth 0.23 g of oxymethyl-N-methylpyrrolidinium hydroxide was added, and it reacted for 2 hours, taking inhalation of nitrogen at 5 L / min at 130 degreeC. After the completion of the reaction, the mixture was kept at 25 ° C for 1 hour under a reduced pressure of 1 mmHg. The dew point was returned to normal pressure with argon gas at -60 ° C and used for analysis. The content of N-methylpyrrolidine-HBF ₄ salt was below the detection limit (10 ppm).

Example 4

Aqueous solution of N-methoxymethyl-N-methylpyrrolidinium hydroxide to 100 g of N-methoxymethyl-N-methylpyrrolidinium tetrafluoroborate containing 410 ppm of N-methylpyrrolidin / HBF ₄ salt 1.0 g (5% by weight) was added and reacted for 2 hours while inhaling nitrogen at 5 L / min at 120 ° C. After the completion of the reaction, the mixture was kept at 25 ° C for 1 hour under a reduced pressure of 1 mmHg. The content of N-methylpyrrolidine-HBF ₄ salt was below the detection limit (10 ppm).

Example 5

50 g of triethylmethylammonium tetrafluoroborate containing 100 ppm of triethylamine and HBF ₄ salt are dissolved in 70 g of methyl alcohol, and methyl alcohol of N, N, N-triethyl-N-methylammonium hydroxide. 0.2 g of a solution (20 wt%) was added and reacted for 12 hours while inhaling nitrogen at 5 L / min at 120 ° C. The content of triethylamine-HBF ₄ salt was below the detection limit (10 ppm).

Example 6

50 g of triethylmethylammonium tetrafluoroborate containing 100 ppm of triethylamine and HBF ₄ salts were dissolved in 50 g of water, and an aqueous solution of N, N, N-triethyl-N-methylammonium hydroxide (35 weight %) 0.1 g was added and reacted for 12 hours, inhaling nitrogen at 5 L / min at 120 degreeC. The content of triethylamine-HBF ₄ salt was below the detection limit (10 ppm).

According to the present invention, it is possible to reduce the protic acid salts of the tertiary amine and the tertiary amine contained as impurities in the quaternary ammonium salt.

The quaternary ammonium salt which reduced impurities can be used suitably as electrolyte of electrical storage elements, such as an electric double layer capacitor and an electrolytic capacitor.

In addition, the electric double layer capacitor and the electrolytic capacitor using the electrolyte can improve the breakdown voltage and long-term reliability.

Claims (4)

(1) A quaternary ammonium hydroxide or quaternary ammonium carbonate is added to a quaternary ammonium salt containing a protonate of a tertiary amine as an impurity, and the protonate of the tertiary amine is added to quaternary ammonium. Neutralized with hydroxide or quaternary ammonium carbonate to convert to tertiary amine and water, while the quaternary ammonium hydroxide or quaternary ammonium carbonate is converted to quaternary ammonium salt, (2) A method for producing a high purity quaternary ammonium salt, wherein the produced tertiary amine and water are removed out of the system, The protonate of the protonate of the tertiary amine is CF ₃ CO ₂ H, CF ₃ SO ₃ H, HBF ₄ , HAlF ₄ , HClBF ₃ , (FSO ₂ ) ₂ NH, HPF ₆ , HAsF ₆ , HClO ₄ , NH (CF ₃ SO ₃ ) ₂ , HC (CF ₃ SO ₃ ) ₃ , RfSO ₃ H, RfCO ₂ H (where Rf represents a fluoroalkyl group having 1 to 8 carbon atoms), (R ^r1 SO ₂ ) (R ^r ₂ SO ₂ ) NH, or (R ^r1 SO ₂ ) (R ^r2 CO ₂ ) H, provided that R ^r1 and R ^r2 represent a fluoroalkyl group having 1 to 8 carbon atoms, and R ^r1 and R ^r2 may be the same or different. May be used), The anion of the quaternary ammonium ^{_{salt, CF 3 CO 2 -, CF}} 3 SO 3 -, BF 4 -, AlF 4 -, ClBF 3 -, (FSO 2) 2 N -, PF 6 -, AsF 6 -, ClO ^{_{4 -, N (CF 3 SO}} 3) 2 -, C (CF 3 SO 3) 3 -, RfSO 3 -, RfCO 2 - ( However, Rf represents a fluoroalkyl group having 1 to 8), (R ^{r1 _{SO 2) (R r2 SO 2}} ) N -, or _{^{(R r1 SO 2) (R}} r2 CO 2) - ( However, R ^r1, R ^r2 represents a fluoroalkyl group having 1 to 8, R ^r1, R ^r2 may be the same or different), A method for producing a high purity quaternary ammonium salt, wherein the high purity quaternary ammonium salt contains 10 ppm or less of the protonate of the tertiary amine. (1) reacting a tertiary amine with an alkyl halide which may have a substituent to obtain a quaternary ammonium halide salt, (2) an acid compound is reacted to obtain a quaternary ammonium salt containing a tertiary amine protic acid salt as an impurity, (3) To this, quaternary ammonium hydroxide or quaternary ammonium carbonate is added, and the protonate of the tertiary amine is neutralized with quaternary ammonium hydroxide or quaternary ammonium carbonate to form tertiary amine And quaternary ammonium hydroxide or quaternary ammonium carbonate to quaternary ammonium salt (4) A method for producing a high purity quaternary ammonium salt, wherein the produced tertiary amine and water are removed from the system; The protonate of the protonate of the tertiary amine is CF ₃ CO ₂ H, CF ₃ SO ₃ H, HBF ₄ , HAlF ₄ , HClBF ₃ , (FSO ₂ ) ₂ NH, HPF ₆ , HAsF ₆ , HClO ₄ , NH (CF ₃ SO ₃ ) ₂ , HC (CF ₃ SO ₃ ) ₃ , RfSO ₃ H, RfCO ₂ H (where Rf represents a fluoroalkyl group having 1 to 8 carbon atoms), (R ^r1 SO ₂ ) (R ^r ₂ SO ₂ ) NH, or (R ^r1 SO ₂ ) (R ^r2 CO ₂ ) H, provided that R ^r1 and R ^r2 represent a fluoroalkyl group having 1 to 8 carbon atoms, and R ^r1 and R ^r2 may be the same or different. May be used), The anion of the quaternary ammonium ^{_{salt, CF 3 CO 2 -, CF}} 3 SO 3 -, BF 4 -, AlF 4 -, ClBF 3 -, (FSO 2) 2 N -, PF 6 -, AsF 6 -, ClO ^{_{4 -, N (CF 3 SO}} 3) 2 -, C (CF 3 SO 3) 3 -, RfSO 3 -, RfCO 2 - ( However, Rf represents a fluoroalkyl group having 1 to 8), (R ^{r1 _{SO 2) (R r2 SO 2}} ) N -, or _{^{(R r1 SO 2) (R}} r2 CO 2) - ( However, R ^r1, R ^r2 represents a fluoroalkyl group having 1 to 8, R ^r1, R ^r2 may be the same or different), A method for producing a high purity quaternary ammonium salt, wherein the high purity quaternary ammonium salt contains 10 ppm or less of the protonate of the tertiary amine. The process according to claim 2, wherein the acid compound is CF ₃ CO ₂ H, CF ₃ SO ₃ H, HBF ₄ , HAlF ₄ , HClBF ₃ or (FSO ₂ ) ₂ NH. delete